The company said this enables manufacturers to rapidly change between different materials, reducing setup times and costs, and eliminates edge rounding normally associated with pad polishing. The system causes fewer visual sleeks, according to Engis, while achieving surface flatness to λ/8 and a scratch-dig rating of 20-10.

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations. Its high coefficient of thermal expansion and its tendency to absorb moisture limit its range of application.

A colorless, crystalline compound whose low refractive index (n = 1.38) makes it effective as a lens antireflection coating when deposited by thermal evaporation in a near vacuum. This process develops a coating that is robust and stable, though only a few molecules thick.